Bottom Line:
In Group I, the mean CMV load was significantly higher than in Group II, and the clinical condition of Group I patients was poorer.In addition, CMV presence was often preceded by another herpesvirus.The results suggest that other herpesviruses, mainly HHV-7, could predispose CMV to cause chronic infection.

Background: The natural history of cytomegalovirus (CMV) infection and disease in transplant recipients prompts researchers to look for other factors contributing to this infection. The ubiquity of lymphotropic herpesviruses (EBV, HHV-6, and HHV-7) and the possibility of their activation during immunosuppression may suggest their participation in progression of CMV infection in patients after hematopoietic stem cell transplantation (HSCT).

Material/methods: The presence of CMV, EBV, HHV-6 and HHV-7 was confirmed through detection of viral DNA isolated from leukocytes. Allo-HSCT recipients (n=55) were examined repeatedly within the average period of 14±7.3 months post-transplant.

Results: CMV DNA was detected in 24% of samples, while EBV, HHV-6 and HHV-7 were detected in 20%, 15% and 14% of samples, respectively. Based on the presence of CMV infection at particular time-points (months) after transplantation, the recipients were divided into 3 groups: Group I (N=15) with persistent infection, Group II (N=20) with transient infection, and Group III (N=20) without CMV infection. In Group I, the mean CMV load was significantly higher than in Group II, and the clinical condition of Group I patients was poorer. All these patients manifested clinical symptoms, and all had episodes of GvHD. All Group I patients developed multiple infections; EBV in 80%, HHV-6 in 47% and HHV-7 in 87% of patients. In the remaining groups, with the exception of HHV-6 in group II, the frequency of infected patients was lower. In addition, CMV presence was often preceded by another herpesvirus.

Conclusions: The results suggest that other herpesviruses, mainly HHV-7, could predispose CMV to cause chronic infection.

f1-medscimonit-17-8-cr432: Distribution of EBV, HHV-6 and HHV-7 in patients belonging to various groups.

Mentions:
Serological examinations before transplantation had shown that the majority of transplant recipients were EBV-seropositive, only 5 persons were seronegative (2 in Group II and 3 in Group III), and all of them had obtained cell-grafts from EBV-seronegative donors. After transplantation, EBV DNA was detected in 12 (80%) patients in Group I, in 13 (65%) patients in Group II and in 10 (50%) recipients in Group III (Figure 1). The presence of HHV-6 DNA was confirmed in 7 (47%) patients in Group I, 13 (65%) in Group II, and in 7 (35%) in Group III. The detection pattern of HHV-7 in patients belonging to the above-mentioned groups was as follows: 13 (87%), 7 (35%) and 5 (25%), respectively (Figure 1). The incidence of HHV-7 infection in Group I was statistically more frequent than in Group II and Group III (Fisher’s exact test, p=0.0027 and p=0.0004, respectively). No such relationship was observed for the remaining viruses investigated.

f1-medscimonit-17-8-cr432: Distribution of EBV, HHV-6 and HHV-7 in patients belonging to various groups.

Mentions:
Serological examinations before transplantation had shown that the majority of transplant recipients were EBV-seropositive, only 5 persons were seronegative (2 in Group II and 3 in Group III), and all of them had obtained cell-grafts from EBV-seronegative donors. After transplantation, EBV DNA was detected in 12 (80%) patients in Group I, in 13 (65%) patients in Group II and in 10 (50%) recipients in Group III (Figure 1). The presence of HHV-6 DNA was confirmed in 7 (47%) patients in Group I, 13 (65%) in Group II, and in 7 (35%) in Group III. The detection pattern of HHV-7 in patients belonging to the above-mentioned groups was as follows: 13 (87%), 7 (35%) and 5 (25%), respectively (Figure 1). The incidence of HHV-7 infection in Group I was statistically more frequent than in Group II and Group III (Fisher’s exact test, p=0.0027 and p=0.0004, respectively). No such relationship was observed for the remaining viruses investigated.

Bottom Line:
In Group I, the mean CMV load was significantly higher than in Group II, and the clinical condition of Group I patients was poorer.In addition, CMV presence was often preceded by another herpesvirus.The results suggest that other herpesviruses, mainly HHV-7, could predispose CMV to cause chronic infection.

Background: The natural history of cytomegalovirus (CMV) infection and disease in transplant recipients prompts researchers to look for other factors contributing to this infection. The ubiquity of lymphotropic herpesviruses (EBV, HHV-6, and HHV-7) and the possibility of their activation during immunosuppression may suggest their participation in progression of CMV infection in patients after hematopoietic stem cell transplantation (HSCT).

Material/methods: The presence of CMV, EBV, HHV-6 and HHV-7 was confirmed through detection of viral DNA isolated from leukocytes. Allo-HSCT recipients (n=55) were examined repeatedly within the average period of 14±7.3 months post-transplant.

Results: CMV DNA was detected in 24% of samples, while EBV, HHV-6 and HHV-7 were detected in 20%, 15% and 14% of samples, respectively. Based on the presence of CMV infection at particular time-points (months) after transplantation, the recipients were divided into 3 groups: Group I (N=15) with persistent infection, Group II (N=20) with transient infection, and Group III (N=20) without CMV infection. In Group I, the mean CMV load was significantly higher than in Group II, and the clinical condition of Group I patients was poorer. All these patients manifested clinical symptoms, and all had episodes of GvHD. All Group I patients developed multiple infections; EBV in 80%, HHV-6 in 47% and HHV-7 in 87% of patients. In the remaining groups, with the exception of HHV-6 in group II, the frequency of infected patients was lower. In addition, CMV presence was often preceded by another herpesvirus.

Conclusions: The results suggest that other herpesviruses, mainly HHV-7, could predispose CMV to cause chronic infection.